if (not defined $ARGV[0]) {
    print "Usage: $0 module_name [diff]\n";
    exit;
}
if ($ARGV[1] and $ARGV[1] eq "diff") {
    my $empty = `$^X -e 'use Module::Versions::Report'`;
    my $full  = `$^X -e 'use $ARGV[0]; use Module::Versions::Report'`;
    require Text::Diff;
    print Text::Diff::diff(\$empty, \$full);
} else {
    eval "use $ARGV[0]";
    eval "use Module::Versions::Report";
}